JPH0451367B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle height adjustment device, particularly to a vehicle height adjustment device that is capable of lowering the vehicle height as much as possible when the vehicle is stopped, in order to improve the ease of getting on and off the vehicle and the ease of loading and unloading luggage. It is something.

As shown in FIG. 1, a vehicle height adjustment device generally includes a pair of left and right air springs 1, 1 provided between a sprung member and an unsprung member of a vehicle;
Air compressor 2 that supplies compressed air to 1
When the vehicle height increases, compressed air is supplied from the air compressor 2 and air tank 3 to the air springs 1 and 1 through the air supply valve 4 to raise the vehicle height and prevent the vehicle height from decreasing. Exhaust valve 5 when it reaches the area
The compressed air from the air springs 1, 1 is discharged to the outside through the air springs 1, 1 to lower the vehicle height. In the figure, 6 is a pressure switch provided in the air tank 3, and when the pressure in the air tank 3 is below a predetermined value, the pressure switch 6 drives the motor M of the air compressor 2 to supply compressed air. is supplied to the air tank 3, and when the pressure inside the air tank 3 reaches a predetermined value, the drive of the motor M is stopped to keep the pressure inside the air tank 3 constant.
7 is air compressor 2 to air tank 3
The dryers 8, 9, and 10 are check valves for removing moisture contained in the compressed air supplied to the dryers 8, 9, and 10. Further, 11 indicates a vehicle height detection sensor, 12 indicates a controller, and the vehicle height detection sensor 1
1 detects the vehicle height, and in the vehicle height up region, the controller 12 opens the air intake valve 4 and supplies compressed air to the air springs 1, 1 to raise the vehicle height, and conversely, in the vehicle height down region The controller 12 opens the exhaust valve 5 and discharges compressed air from the air springs 1, 1 to lower the vehicle height.

By the way, in the conventional vehicle height adjustment device of this type, the bumper rubber 13 and the rubber receiver 14 are fixed to the upper shell 1a and lower shell 1b of the air spring 1, as shown in FIG. Due to the presence of the receiver 14, the amount of vehicle height reduction δ relative to the standard attitude can only be estimated by adding the deflection amount δ ₂ of the bumper rubber due to the sprung weight to the buffer clearance δ ₁ (that is, δ = δ ₁ + δ ₂ ); Even when it is desired to lower the vehicle height as much as possible when the vehicle is stopped in order to improve the ease of getting in and out of the vehicle and loading and unloading cargo, the drawback is that the vehicle height cannot be lowered sufficiently.

The present invention has been made for the purpose of solving the above-mentioned conventional drawbacks, increasing the amount of vehicle height reduction as much as possible when the vehicle is stopped, and improving the ease of getting on and off the vehicle and the ease of loading and unloading luggage. The gist of the configuration is the conventional vehicle height adjustment device as described above, a piston, a cylinder to which the piston is slidably attached, and an oil pump for injecting working oil into the cylinder. Either one of the hydraulic system components of the piston is attached to either the sprung member or the unsprung member to serve as a fixed member, and the other hydraulic system component is a movable member movable in the buffer direction, and this movable member Attach one of the bumper rubber or the rubber receiver to the sprung member or the unsprung member, and attach the other bumper rubber or rubber receiver to the other of the sprung member or unsprung member, and when the vehicle is stopped, the bumper rubber and rubber The reason is that the relative position with the receiver is spaced apart from each other compared to the position in the standard running state.

Next, the present invention will be explained based on the drawings from FIG. 3 onwards. Note that parts that are the same as those in the prior art are designated by the same reference numerals and redundant explanations will be omitted.

FIG. 3 shows an embodiment in which a bumper rubber is attached to a piston. In the figure, 15 is a hydraulic system, which includes a piston 16, a cylinder 17, an oil pump 18, and an oil tank 1.
9, check valve 20, relief valve 21,
A discharge valve 22 is provided, and the cylinder 17 is provided with a discharge valve 22.
is attached to the sprung member of the vehicle as a fixed member, and the piston 16 is a movable member that expands and contracts toward the unsprung member.

During general driving, oil pump 1
8 drives the motor M of the oil tank 19 to feed the working oil from the oil tank 19 into the cylinder 17 as a fixed member through the check valve 20, and pushes down the piston 16 as a movable member below the cylinder 17. A desired buffer clearance is provided between the piston 16 and the rubber receiver 14 fixed to the unsprung member, and a piston reaction force F=a greater than the input to the bumper rubber 13 is applied to the piston 16.
(Effective cross-sectional area of piston) x P (inner cylinder pressure)
is now being granted. It is desirable that the motor automatically stop when the piston 16 descends to a predetermined position. When the vehicle is stopped, the exhaust valve 22 is opened to release the pressure inside the cylinder 17 (at the same time as the oil pump 18 is stopped).

The relief valve 21 relieves the pressure when the piston 16 comes into contact with the lower end of the cylinder and the pressure inside the cylinder 17 increases abnormally.
The oil pump 18 is protected from abnormal pressure.

Note that 23 indicates a fixed portion of the unsprung member.

The vehicle height adjustment device of the first embodiment has the above-mentioned configuration, and during normal driving, a reaction force F greater than the input to the bumper rubber 13 is applied to the piston 16 as a movable member. Even if the rubber 13 exceeds the desired bumper clearance and collides with the rubber receiver 14, the piston 16 as a movable member will not be pushed up against the reaction force F, and therefore the bumper rubber 13 will effectively function. fulfill When the vehicle is stopped, the exhaust valve 22 is opened (at the same time as the oil pump 18 is stopped) to release the pressure inside the cylinder 17, which is a fixed member, so compressed air is exhausted from the air springs 1, 1 and the vehicle height is lowered. When lowered, the bumper rubber 13 comes into contact with the rubber receiver 14, but the bumper rubber 13 to the piston 16 are pushed upward toward the cylinder 17 while being pushed by the rubber receiver 14.
Therefore, the vehicle height decreases by the amount δ that is pushed up.
This makes it possible to increase the

FIG. 4 shows an embodiment in which the rubber receiver 14 is attached to the piston 16, and the bumper rubber 13
This is the same as the embodiment shown in FIG. 3, except that the rubber receiver 14 is attached to the fixed portion 23 of the unsprung member and the rubber receiver 14 is attached to the piston 16.

FIG. 5 shows a case where the oil pump 25 of the power steering 24 is shared as the oil pump 18, and other parts are the same as the embodiment shown in FIG.

Figure 6 also shows the bumper rubber 13 being connected to the air spring 1.
An embodiment is shown in which the bumper rubber 13 is attached to the piston 16 via the top shell 1a and a rotation bracket 24, and in this embodiment, the bumper rubber 13 is moved up and down by the piston 16 together with the top shell 1a.

In the embodiment shown in the drawings, the cylinder 17 of the hydraulic device 15 is attached as a fixed member to the sprung member of the vehicle, and the piston 16 is used as the movable member. Attachment, the cylinder 17 may be a movable member.

Further, the piston 16 or the cylinder 17 may be attached to an unsprung member to serve as a fixed member.

Since the vehicle height adjustment device of the present invention has the configuration described above, the vehicle height can be adjusted by stopping the drive of the oil pump when the vehicle is stopped and allowing the operating oil in the cylinder to drain into the oil tank or the like. When lowered, the bumper rubber comes into contact with the rubber receiver and pushes the piston, and the piston continues to move as it is pushed, increasing the amount of vehicle height reduction and improving ease of getting on and off and loading and unloading cargo. can be advantageously improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional vehicle height adjustment device, Fig. 2 is a sectional view of the same air spring, Fig. 3 and the following show embodiments of the hydraulic system of the present invention, and Fig. 3 shows a bumper rubber mounted on a piston. Figure 4 is a partial cross-sectional block diagram when the rubber receiver is installed on the piston. Figure 5 is a block diagram when the power steering oil pump is shared as the oil pump for the hydraulic system. FIG. 6 is a sectional view showing the case where the bumper rubber is attached to the piston via the air spring's upper shell and the rotation bracket. 1... Air spring, 2... Air compressor, 13... Bumper rubber, 14... Rubber receiver, 15... Hydraulic system, 16... Piston, 17
...Cylinder, 18...Oil pump.

Claims (1)

[Scope of Claims] 1. An air spring provided between a sprung member and an unsprung member of a vehicle, and an air compressor that supplies compressed air to the air spring. The vehicle height adjusting device is configured to raise the vehicle height by supplying compressed air to the air spring, and to lower the vehicle height by discharging the compressed air from the air spring when the vehicle height is in a lower region. A hydraulic system is equipped with a cylinder that is slidably attached to the cylinder, and an oil pump that injects working oil into the cylinder. The other hydraulic system component is a movable member movable in the shock absorbing direction, and either a bumper rubber or a rubber receiver is attached to the movable member, and the sprung member or spring A vehicle height adjustment device characterized in that the other of the bumper rubber or the rubber receiver is attached to the other of the lower member. 2. The vehicle height adjustment device according to claim 1, wherein the oil pump of the hydraulic system is a power steering oil pump.